Saturday, January 11, 2014

Links 11/01/14

'Fish that appear drab to human eyes may see each other decked in brilliant greens, reds and oranges, say scientists who have found the first evidence of widespread biofluorescence in the animals.'

 'In spite of its need for moisturizing, the fish has essentially forsaken the sea and spends its entire life on land.'

Fish eats bird.

'Lauren Palladino of Vanderbilt University and her colleagues have now discovered an entirely new class of hypervelocity stars, and they behave quite differently. These 20 newly discovered stars are about the same size as our Sun, so they're relatively small. And surprisingly, none of them appear to come from the galactic core.'

 'There's a new kind of planet to add to Kepler's cornucopia of alien worlds, and you won't findit in Earth's own solar system.Ground-based follow-up observations of planets found by NASA's Kepler spacecraft revealthe masses and densities of 16 new planets ranging between one and four times the size ofEarth. Many of the newfound orbs, described here today (Jan. 6) at a meeting of the AmericanAstronomical Society, have a rocky core surrounded by a puffed-up envelope of gas, whichscientists are calling "sub-Neptunes" or "mini-Neptunes."'

Astronomers say that they have discovered the first example of a long-sought cosmic oddity: a bloated, dying star with a surprise in its core — an ultradense neutron star.

Portrait of a star about to go supernova.

 'Striking new observations with the Atacama Large Millimeter/submillimeter Array (ALMA) telescope capture, for the first time, the remains of a recent supernova brimming with freshly formed dust. If enough of this dust makes the perilous transition into interstellar space, it could explain how many galaxies acquired their dusty, dusky appearance.'

 Credit: NASA, ESA, and B. Siana and A. Alavi (University of California, Riverside)
The Hubble Telescope has imaged 58 young, small galaxies, part of a vast sea of faint galaxies that existed more than 10 billion years ago, during the heyday of star birth.

Tuesday, January 07, 2014

Things I Found On Google Street View #1

The house formerly owned by J.G. Ballard.

Monday, January 06, 2014

Relative Dimensions In Space

                                      Composite by Tom Buckley-Houston

This image of the Moon and the Andromeda galaxy in Earth's night sky (made from an original photo of the Moon taken by Stephen Rahm, and an ultraviolet image from NASA's GALEX mission) was all over the internet last week. It shows how big the Andromeda galaxy would seem if the entire span of its spiral arms was bright enough to see with the naked eye (usually only the core is visible without augmentation). The Andromeda galaxy is 140,000 light years across, but it's 2.5 million light year away. The Moon is just 3400 kilometres in diameter, but it is of course much closer - a little over 360,000 kilometres away at perigee, or 1.282 light seconds. A nice illustration of relative distance and size.

The eponymous artificial world of my Confluence trilogy orbits a black hole where most of the Large Magellanic Cloud used to be. The LMC is a satellite galaxy of the Milky Way, some 163,000 light years from Earth. It's about a tenth of the size of the Andromeda galaxy, but because it is much closer it seems much larger. In Earth's sky the Andromeda galaxy is about 3 angular degrees across (there are, of course, 360 degrees of sky), about six times the size of the Moon. The LMC is about ten degrees across, and the Andromeda Galaxy is about the same size of our Milky Way galaxy, that is, roughly ten times the size of the LMC. So if you stood on Confluence and looked back at the Milky Way on a dark night, it would be about 100 angular degrees across, filling almost a third of the sky. Imagine the sight:
Framed on one side by the bluff on which the Aedile’s house stood, and by the chimneys of the paeonin mill on the other, the triple-armed pinwheel of the galaxy stood beyond the edge of the world.  It was so big that when Yama looked at one edge he could not see the other.  The Arm of the Warrior rose high above the arch of the Arm of the Hunter; the Arm of the Archer curved in the opposite direction, below the edge of the world, and would not be seen again until next winter.  The structure known as the Blue Diadem, that Yama knew from his readings of the Puranas was a cloud of fifty thousand blue-white stars each forty times the mass of the sun of Confluence, was a brilliant pinprick of light beyond the frayed point of the outflung Arm of the Hunter, like a drop of water flicked from a finger.  Smaller star clusters made long chains of concentrated light through the milky haze of the galactic arms.  There were lines and threads and globes and clouds of stars, all fading into a misty radiance notched by dark lanes that barred the arms at regular intervals.  The core, bisected by the horizon, was knitted from thin shells of stars in tidy orbits concentrically packed around the great globular clusters of the heart stars, like layers of glittering tissue wrapped around a heap of jewels.  Confronted with this ancient grandeur, Yama felt that his fate was as insignificant as that of any of the mosquitoes which danced before his face.
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